Field
The disclosed concept relates to vacuum switching apparatus and, in particular, vacuum switching apparatus such as, for example, vacuum interrupters. The disclosed concept also pertains to contact assemblies for vacuum interrupters.
Background Information
Circuit breakers such as, for example, power circuit breakers for systems operating above about 1,000 volts, typically employ vacuum interrupters as the switching devices. Vacuum interrupters generally include separable electrical contacts disposed within an insulating housing. Typically, one of the contacts is fixed relative to both the housing and to an external electrical conductor, which is electrically interconnected with a power circuit associated with the vacuum interrupter. The other contact is part of a movable contact assembly including a stem of circular cross-section and a contact disposed on one end of the stem and enclosed within a vacuum chamber. A driving mechanism is disposed on the other end, external to the vacuum chamber.
The contacts are subjected to significant contact forces, which for example, are associated with relatively high electrical currents. Thus, among other issues, the contacts are susceptible to breaking or bending.
There is, therefore, room for improvement in vacuum switching apparatus, such as vacuum interrupters, and in contact assemblies therefor.